146 RECORDS OF THE AUSTRALIAN MUSEUM. 



merely, gradually enlarging or broadening, and becoming separated 

 by wider and wider intercostal spaces, on the venter somewhat 

 convex forwards, on the dorsum more so, and on the flanks 

 distinctly sigmoidal ; intercostal spaces (or valleys) finely lined. 

 Tubercles very characteristic and confined to the earliest whorls, 

 comprised in from one to three rows on each side the middle line 

 of the venter as prominent, bold nodes; when only one row, this 

 occurs along each abdominal margin ; when two, the second 

 appears at about the middle line of each flank ; and when three, 

 the third is supra-dorsal in position ; when in three series, these 

 nodes gradually die out in the following order — the supra-dorsal 

 disappear first, the flank nodes next, and finally the abdominal 

 nodes on some part of the third whorl. tSepta with very undulat- 

 ing surfaces from the high development of the lobes and saddles. 

 Obs. — It will be remembered that subsequent to my original 

 description of C.jackii, I referred-'' the latter to C. australe, 

 Moore, as the younger stage of the latter. This determination 1 

 can no longer uphold, through my inability to recognise C. 

 australe. I was led to this chiefly by Dr. W. Waagen's concep- 

 tion of C. australe, and still believe that the last named and my 

 C.jackii are one and the same. The acquisition of additional 

 material has increased my knowledge of both the older and 

 younger conditions of C.jackii, and it now appears to be one of 

 our best defined species. 



In a former synonomy I united with C. jackii under the 

 common name C. australe, the late Mr. F. Ratte's figures' 10 of 

 the large Crioceras in the Australian Museum. This monster, 

 when perfect, must have possessed a diameter of upwards of four 

 feet, but its state of preservation is so unsatisfactory that I now 

 feel diffident of passing an opinion on its identity; tubercles are 

 not visible. The largest specimen I feel disposed to refer to this 

 species measures eleven inches by nine inches cross-diameters, 

 the breadth of the last existing whorl being five inches from the 

 middle of the venter to the umbilical edge. 



The general appearance is decidedly ammonoid, particularly 

 that of the Lytoceras group, arising to some extent from the close 

 contiguity of the whorls to one another, although in this feature 

 there is slight variability. In some cases the coil is close, in 

 others there is an appreciable void between the volutions, when 

 the projecting conical tubercles along the ventro-lateral margins 

 become conspicuous. 



29 Etheridge— Geol. Pal. Q'land, etc., 1S92, p. 499. 



•™Ratte— Proc. Linn. ,Soc. N. S. Wales, (2), i., 1SS<>. p. 133, pis. i. and ii. 



